Turbopause internal gravity waves, 557.7 nm airglow, and eddy diffusion coefficient

Abstract

A study of the properties of internal gravity waves by means of observations of the 557.7‐nm emission line has been carried out. Special emphasis was put on the determination of the kinetic energy density of the waves, which have maxima in winter and in summer, and on the determination of the enhanced diffusion tensor K. Values of Kzz, the zz component, important in theoretical models, of the order of 3 × 106 cm² s−1 were obtained, and its seasonal variation exhibits a winter maximum. The enhanced diffusion due to internal gravity waves is highly anisotropic, being the two eigenvalues corresponding to the horizontal degeneration plane of the order of 4 × 109 cm² s−1. The possible relation between K and D region winter anomalous absorption has been also examined.